Quantitative analyses of ROS and RNS production in breast cancer cell lines incubated with ferrocifens.

Ferrocifens are an original class of ferrocifen-type breast cancer drugs. They possess anti-proliferative effects due to the association of the ferrocene moiety and the tamoxifen skeleton. In this work, fluorescence measurements indicated the production of reactive oxygen species (ROS) if hormone-dependent or -independent breast cancer cells were incubated with three hit ferrocifen compounds. Additionally, amperometry at ultramicroelectrodes was carried out to identify and quantify ROS and reactive nitrogen species (RNS) under stress conditions. Videomicroscopy was used to optimize the conditions employed for electrochemical investigations. Amperometry was then performed on two cell lines pre-incubated with each of the three ferrocifens. Interestingly, these results demonstrate that the presence of an aminoalkyl chain in the ferrocifen structure may confer a unique behavior toward both cell lines, in comparison with the two other compounds that lack this feature.